RE: [PATCH net-next V2] dt-bindings: net: ethernet-controller: Add ptp-hardware-clock

From: Gaddam, Sarath Babu Naidu
Date: Thu Jan 19 2023 - 05:53:20 EST




> -----Original Message-----
> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> Sent: Thursday, November 10, 2022 7:36 PM
> To: Gaddam, Sarath Babu Naidu
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> <radhey.shyam.pandey@xxxxxxx>; Sarangi, Anirudha
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> <harini.katakam@xxxxxxx>; git (AMD-Xilinx) <git@xxxxxxx>
> Subject: Re: [PATCH net-next V2] dt-bindings: net: ethernet-controller:
> Add ptp-hardware-clock
>
> On 10/11/2022 10:57, Gaddam, Sarath Babu Naidu wrote:
> >>>
> >>> + ptp-hardware-clock:
> >>> + $ref: /schemas/types.yaml#/definitions/phandle
> >>> + description:
> >>> + Specifies a reference to a node representing a IEEE1588 timer.
> >>
> >> Drop "Specifies a reference to". It's obvious from the schema.
> >>
> >> Aren't you expecting here some specific Devicetree node of IEEE1588
> timer?
> >> IOW, you expect to point to timer, but what this timer must provide?
> >> How is this generic?
> >
> > Thanks for review comments.
> > Format can be as documented by users
> Documentation/devicetree/bindings/ptp/ members. The node should be
> accessible to derive the index but the format of the PTP clock node is
> upto the vendor.
>
> I am not sure what do you mean here. Anyway description might need
> something more specific.

Apologies for picking up on this thread after a long time.
PTP clock node(timer) is upto the vendor. Driver which needs a reference
to this node can be accessed by this new property. I will update the
description.

> >
> >
> >>
> >> In your commit msg you use multiple times "driver", so are you
> adding
> >> it only to satisfy Linux driver requirements? What about other
> >> drivers, e.g. on BSD or U-Boot?
> >
> > AFAIK this is for Linux. It is not relevant to uboot as there's no PTP
> support there.
>
> And BSD? Bindings are not for Linux only. Please abstract from any OS
> specifics.

This new binding is a generic property. It can be used in other
drivers also if they want to access the PTP device node in the
current driver and It's an optional property.

I will change the commit description as below. If this is fine, I
will send another version with updated commit description.

"There is currently no standard property to pass PTP device index
information to ethernet driver when they are independent.

ptp-hardware-clock property will contain phandle to PTP clock node.

Its a generic (optional) property name to link to PTP phandle to
Ethernet node. Any future or current ethernet drivers that need
a reference to the PHC used on their system can simply use this
generic property name instead of using custom property
implementation in their device tree nodes."

Thanks,
Sarath

> Also your messages needs wrapping. Use mailing list reply style.
>
> Best regards,
> Krzysztof